Micro-speaker

Abstract

A micro-speaker includes a frame, a yoke, a magnet, a diaphragm, and a voice coil. The yoke includes a base wall and a plurality of sidewalls defining a number of flat walls and a number of curved walls disposed at corners of the yoke. The flat walls define a number of first steps disposed at an upper level for engaging with the position blocks, the curved walls define a number of second steps disposed at a lower level for air leaking.

What is claimed is: 
     
       1. A micro-speaker, comprising:
 a frame including a plurality of walls forming a cavity and a plurality of position blocks extending from inner face of the walls into the cavity; 
 a yoke received in the cavity, including a base wall and a plurality of sidewalls extending vertically from a periphery of the base wall, the sidewalls defining a plurality of flat walls and a plurality of curved walls disposed at corners of the yoke; 
 a magnet disposed at a central portion of the base wall and forming a magnetic gap corporately with the yoke; 
 a diaphragm; 
 a voice coil disposed in the a magnetic gap for driving the diaphragm; wherein 
 the flat wall defines a first step disposed at an upper level for engaging with the position blocks of the frame, the curved wall defines a second step disposed at a lower level for air leaking. 
 
     
     
       2. The micro-speaker as claimed in  claim 1 , wherein the yoke is substantially rectangular and includes four flat walls and four curved walls each connecting two adjacent flat walls. 
     
     
       3. The micro-speaker as claimed in  claim 2 , wherein the first step is adjoined the second step, and a distance from the first step to the base wall of the yoke is longer than a distance from the second step to the base wall. 
     
     
       4. The micro-speaker as claimed in  claim 3 , wherein each position block cooperates with the first step. 
     
     
       5. The micro-speaker as claimed in  claim 1 , wherein the micro-speaker is provided with an upper cover and a lower cover with the frame disposed therebetween. 
     
     
       6. The micro-speaker as claimed in  claim 5 , wherein the lower cover includes a bottom plate mounted to the yoke. 
     
     
       7. A micro-speaker, comprising:
 a frame with a plurality of position blocks; 
 a magnetic circuit unit accommodated in the frame, including a yoke with a base wall and a plurality of sidewalls extending vertically from the base wall, a magnet disposed on the base wall and forming a magnetic gap corporately with the sidewalls; 
 a vibrating unit including a diaphragm and a voice coil connected with the diaphragm; wherein 
 a plurality of outlets are disposed on an upper side of the sidewalls, each outlet defining a first step disposed at an upper level for supporting the position block and a second step adjoined with the first step and disposed at a lower level. 
 
     
     
       8. The micro-speaker as claimed in  claim 7 , wherein the sidewalls includes four flat walls and four curved walls, each curved wall connecting two adjacent flat walls. 
     
     
       9. The micro-speaker as claimed in  claim 8 , wherein the first steps are disposed on the flat walls, the second steps are disposed on the curved walls. 
     
     
       10. The micro-speaker as claimed in  claim 9 , wherein a curved surface is disposed between each first step and second step. 
     
     
       11. The micro-speaker as claimed in  claim 10 , wherein each position block is partially supported by the first step with the rest part thereof suspending above the second step. 
     
     
       12. A micro-speaker, comprising:
 a frame including a plurality of walls forming a cavity and a plurality of position blocks extending from inner face of the walls into the cavity; 
 a yoke accommodated in the cavity, including a base wall and a plurality of sidewalls extending vertically from a periphery of the base wall, the sidewalls defining a plurality of flat walls and a plurality of curved walls, each curved wall connecting two adjacent flat walls and disposed at a corner of the yoke, the flat walls defining a plurality of first steps at an upper level for engaging with the position blocks, the curved walls defining a plurality of second steps at a lower level. 
 
     
     
       13. The micro-speaker as claimed in  claim 12 , wherein the frame includes four position blocks disposed on the first steps.